Can now pass the fullpath to a project as a command line argument to the PipelineTool to open that project after startup (eg, associate .mgcb files with PipelineTool.exe).
Merge branch 'PipelineToolOpenFile' into PipelineTool_OpenProject_CommandLine

Conflicts:
	Tools/Pipeline/Windows/MainView.Designer.cs
	Tools/Pipeline/Windows/MainView.cs
Merge pull request #2682 from SickheadGames/PipelineTool_OpenProject_CommandLine

PipelineTool command line argument 'project to open'